<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<h2>JavaScript 能做什么？</h2>

<p>JavaScript 能够改变 HTML 属性值。</p>

<p>在本例中，JavaScript 改变了图像的 src 属性值。</p>

<button onclick="document.getElementById('myImage').src='./img/eg_bulbon.gif'">开灯</button>

<img id="myImage" border="0" src="./img/eg_bulboff.gif" style="text-align:center;">

<button onclick="document.getElementById('myImage').src='./img/eg_bulboff.gif'">关灯</button>
</body>
</html>
